I know it might be very frustrating when you find the perfect cake recipe and you realise you don’t own a pan with the same size as indicated. Because I want to help you to adapt your cake pans to any recipe, I created this Cake Pan Size Conversions Calculator.
How to use this Calculator
This calculator will help you to calculate the necessary ingredients for the pan that you have. You can also convert rectangular to round pans and vice versa. It works both in cm and inches. The resulting number shows you how many times you need to multiply the recipe ingredients. If your pan is smaller than the one in the recipe, this number will be smaller than 1. If your pan is bigger, it will be higher than 1.
The calculated number is approximate and should be used as a point of reference. You may want to round it up, especially when you have ingredients that can’t be divided easily (e.g. eggs).
Let’s take an example: if you have a 23 cm cake pan and the recipe indicates 17 cm, the calculator shows that you would need to multiply the ingredients by 1,83. In this case consider how many eggs the original recipe calls for: if it calls for 3 eggs, multiplied by 1,8 makes 5,4 eggs. Dividing eggs is not very practical, so the best option is to use 5 eggs for your recipe. In order to ensure that all other ingredients have the same proportion, you might divide 5 by 3 and find the eggs proportion: it is 1,66. Keeping the same proportion would guarantee you that the balance between wet and dry ingredients is maintained (very important for cakes) so the best approach would be to multiply the rest of the ingredients by 1,66. Again, feel free to round up the resulting numbers.
- Please note that this calculator takes in consideration only the surface area of the pans: their height is not calculated. In my view heigh is not so relevant in many cases as we don’t usually fill up the pan till the top (sometimes I even fill it less than half). Usually the smaller pans are higher than the big ones, therefore you might want to round up the result to the lower number. In the example we reviewed if the number of the eggs was 4, it would be most convenient to increase the ingredients with 50%, so that the eggs become 6. To do that you need to multiply all the ingredients by 1,5.
- You don’t really need to use the calculator if your round cake pan is 1-2 cm smaller or bigger than the original one (e.g. 18 to 20 cm) In case of inches, one inch difference is worth a calculation.
- Beware that changing the pans might change the baking time. Taller cakes take more time to bake. It might turn out that a cake bakes faster in a larger pan as it is lower. Always test the cakes with a toothpick after about 30 minutes in the oven.
I hope this calculator is useful for you! In case you have any questions or feedback, please feel free to share them with me. This project is my experiment so it can be updated. I would really appreciate your valuable input on it!